Diablo – When can I get Adria’s conversations for the Bewitched achievement

TP to town at the very beginning of Act 4 Quest 1 (Fall of the High Heavens) for "A Lost Friend", "A Dark Outlook", and "Adria's Betrayal"

The Enchantress's "Eirena's Journey" is available for most of Act 2 (from the very beginning), but Act 2 Quest 2 (The Road to Alcarnus) will spawn you right next to her:

Conversation availability does not change between difficulties, but some conversations are only available for brief periods (esp. with the jeweler and blacksmith). You can load these levels and get them immediately, though. For what it's worth, those A4Q1 conversations above were the most elusive of the lot.

Based on a rough timeline of the data I collected, there are 23 points during the game that have to be hit to complete all the conversation achievements and, because of dependencies, they need to be hit in order. When talking to someone, you are expected to complete all their available conversations before moving on to talk to someone else, but I only count the conversations that count towards achievements despite there being additional extra conversations available. I will try to group conversations to cut down travel time, making this pretty close to the fewest stops with the least travel, but there is probably some room for optimization once all dependencies are mapped out. Don't worry about avoiding people with asterisks because you will get those conversations later and this way involves less running around. I'll go through and confirm specifics and nuances later to determine if there are inconsistencies to timing and number of conversations based on current objective and dependencies.

Act I

1. The Fallen Star - Rumford at the Gates: Takes you right to town. Talk to Haedrig and then Leah for 1 conversation each.
2. The Legacy of Cain - Begin Quest: Talk to Leah to begin the quest. Talk to Haedrig and then Leah for 1 conversation each.
3. A Shattered Crown - Begin Quest: Talk to Haedrig for 1 conversation. Talk to Deckard Cain to begin the quest and then talk to Leah for 2 conversations, Deckard Cain for 4 conversations and then Covetous Shen for 4 conversations.
4. Reign of the Black King - The Royal Crypts: Talk to Haedrig for 2 conversations and then Covetous Shen for 1 conversation. Deckard Cain has a conversation that you get by completing the quest, but you should have this one already since you beat the game - if you want to re-listen to it, you can get it at the next point.
5. Sword of the Stranger - Khazra Den: Talk to The Stranger for 1 conversation, then Deckard Cain for 2 conversations, and then Covetous Shen for 1 conversation.
6. The Broken Blade - Talk to Alaric: Talk to The Stranger for 1 conversation. You will need to run through the act a bit to get Leah's 2 conversations as she follows you, 1 while collecting beacons and 1 at the drowned temple.
7. The Doom in Wortham - Begin Quest: Talk to Deckard Cain for his last 4 conversations, and Haedrig and Covetous Shen for 1 conversation each. Talk to The Stranger to begin the quest. Talk to The Stranger again and then Covetous Shen for 1 conversation each.
8. Trailing the Coven - Khazra Barricade: Talk to Leah and then Covetous Shen for 1 conversation each.
9. The Imprisoned Angel - The Cursed Hold: Talk to Covetous Shen for 1 conversation.
10. Return to New Tristram - Begin Quest: Talk to Tyrael twice, Haedrig, and then Covetous Shen for 1 conversation each.

Act II

11. A Royal Audience - Begin Quest: Talk to Eirena for 3 conversations, Haedrig for 3 conversations and then Covetous Shen for 6 conversations.
12. Blood and Sand - Begin Quest: Talk to Leah for 3 conversations, Adria for 9 conversations, Tyrael for 8 conversations, and Covetous Shen for 1 conversation.
13. The Black Soulstone - Realm of Shadow: Waypoint to The Archives of Zoltun Kulle and talk to Leah for 1 conversation.
14. The Scouring of Caldeum - Begin Quest: Talk to Adria, Haedrig and Covetous Shen for 3 conversations each.

Act III

15. The Siege of Bastion's Keep - Light the Beacons: Talk to Tyrael for 2 conversations. Town Portal. Talk to Haedrig for 3 conversations.
16. Turning the Tide - Begin Quest: Talk to Tyrael to begin the quest. Talk to Tyrael for 4 conversations and Haedrig for 1 conversation. Enter the Armory and talk to Adria for 2 conversations and Leah for 3 conversations.
17. The Breached Keep - Find the Breach: Talk to Tyrael for 3 conversations and Kormac for 11 conversations.
18. Tremors in the Stone - Begin Quest: Talk to Lieutenant Lavail to begin the quest. Talk to Haedrig for 1 conversation and Covetous Shen for 7 conversations.
19. Machines of War - Destroy Ballistae: Talk to Haedrig and Covetous Shen for 1 conversation each. Enter the Armory and talk to Adria for 1 conversation.
20. Heart of Sin - The Second Heart: Talk to Haedrig for 1 conversation and Covetous Shen for 2 conversations.

Act IV

21. Fall of the High Heavens - Begin Quest: Talk to Tyrael several times for 3 conversations. Use the nearby waypoint to Bastion's Keep Stronghold. Talk to Kormac for 4 conversations, Lyndon for 14 conversations, Eirena for 8 conversations, and Covetous Shen for 3 conversations.
22. Beneath the Spire - Begin Quest: Talk to Haedrig for 2 conversations and Covetous Shen for 3 conversations.
23. Prime Evil - Enter the Crystal Arch: Talk to Lyndon for 1 conversation, Eirena for 2 conversations and Covetous Shen for 1 conversation. Use the Waypoint to go to The Pinnacle of Heaven and talk to Tyrael for 5 conversations.